Sonitictis moralesi, gen. et sp. nov, a new hypercarnivorous and durophagous mustelid from middle Miocene Tunggur Formation, Inner Mongolia, China and its functional morphology

ABSTRACT

We name a rare, hypercarnivorous and durophagous mustelid Sonitictis moralesi, new genus and species, in honour of Jorge Morales for his contributions to carnivore palaeontology. Sonitictis moralesi is from the middle Miocene Tunggur Formation of Inner Mongolia, China (Tunggurian Land Mammal age). S. moralesi has a short and robust jaw that deepens slightly behind the m1 and possesses a shallow groove at its ventral surface. Dentally, it has robust premolars and highly hypercarnivorous m1 that has lost the metaconid and a trenchant talonid. Known by three jaw fragments, knowledge of this new mustelid is still poor and its relationship uncertain. However, based on its possession of a ventral groove, robust premolars and hypercarnivorous first molar, we tentatively place it in the subfamily Mellivorinae, which includes modern Mellivora capensis (honey badger) and extinct species of Eomellivora, plus others. We conducted mandibular force profile analyses on one S. moralesi specimen and compared bite force estimates to several specimens of E. piveteaui, E. wimani and M. capensis. The results suggest that Sonitictis likely was a more capable predator and consumer of vertebrate prey than the extant Mellivora, reaching the low end of the bite force estimates for the larger and more robust Eomellivora.

KEYWORDS:

• Mustelidae
• middle Miocene
• Tunggur Formation
• Inner Mongolia

Acknowledgments

The fossil collections accumulated during the past 30 years, including the specimens described herein, would be impossible without the dedicated labor by field crews, too numerous to be listed here. We benefited from extensive discussions with Alberto Valenciano about specimens described herein, as well as images and videos that he has provided. In the end, we adopted some of his advice but arrived at a taxonomic identification different from suggestions by Valenciano, which are greatly appreciated. Stuart White did photogrammetry works on the 3D model of the holotype of Sonitictis moralesi (see Data deposition section for download). We thank Richard S. White, Jr. of International Wildlife Museum for donation of a specimen of Eomellivora from China to be repatriated to the IVPP. Yanping Song helped in Photoshop manipulation of photographic images. Chris Conroy facilitated specimen loans from the MVZ and Jim Dines helped with a loan from LACM Mammalogy. We greatly appreciate detailed reviews and edits by Alberto Valenciano, Jon Baskin and Hugh Wagner that substantially improved this paper.

We thank editors of this festschrift volume for the invitation to contribute this paper in honour of Jorge Morales, whom we greatly admire. Over the years, the senior author enjoyed fruitful interactions with Jorge Morales, and benefited from his prodigious knowledge in the evolution of carnivorans from Europe and Africa.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

3D models for the holotype of Sonitictis moralesi, two lower jaws of Mellivora capensis (LACM (M) 23010 and MVZ 184107), one lower jaw of Eomellivora wimani (LACM 162597) and one lower jaw of Canis lupus (LACM (M) 23010) in the functional morphology analysis are deposited at MorphoSource (https://www.morphosource.org/dashboard/collections/000385219/edit?locale=en&). See also Materials and Methods section for weblinks of individual specimens.

Supplementary material

Supplemental data for this article can be accessed here.

Additional information

Funding

This work was supported by the Strategic Priority Research Program of the Chinese Academy of Sciences (XDB26000000, XDA20070203, XDA20070301). Field work and laboratory analysis were supported by funds from the Knowledge Innovation Program of the Chinese Academy of Sciences (KZCX2-YW-120), Major Basic Research Projects (2006CB806400) of MST of China, the CAS/SAFEA International Partnership Program for Creative Research Teams, Chinese Academy of Science Outstanding Overseas Scholar Fund (No. 2004-2-4), Chinese National Natural Science Foundation (Nos. National Natural Science Foundation of China 49872011 and 40128004), National Geographic Society (Nos. 5527-95 and 6004-97).